Definition: You are given a question on college chemistry. You are also given 4 answer options (associated with "A", "B", "C", "D"), out of which only one is correct. You need to answer the question by selecting the correct option. You should only answer with the choice letter, not the whole answer.
Input: Which nuclide has an NMR frequency of 115.5 MHz in a 20.0 T magnetic field?
(A)17O (B)19F (C)29Si (D)31P

A